Improved Semi-Persistent Resource Allocation Behavior for V2x Transmissions

1. A transmitting device for transmitting periodic data via a sidelink interface to one or more receiving devices, wherein the transmitting device autonomously selects radio resources for transmitting periodic and aperiodic data via the sidelink interface, wherein the transmitting device comprises: a transmitter, which in operation, transmits first periodic data together with first scheduling information to the one or more receiving devices, the first scheduling information indicating radio resources used for transmitting the first periodic data and further indicating reserved radio resources usable at a later point in time by the transmitting device to transmit second periodic data; and a processor, which in operation, delays the second periodic data until the later point in time, and wherein the transmitter, when in operation, transmits the second periodic data at the later point in time using the reserved radio resources indicated by the first scheduling information; and wherein the transmitter, when in operation, transmits other data than the first and second periodic data in response to the other data becoming available for transmission, and wherein the first scheduling information includes a field indicating the later point in time for which the radio resources are reserved, wherein the processor, when in operation, determines the later point in time for the reserved radio resources based on a periodicity of the first and second periodic data.

2. The transmitting device according to claim 1 , wherein the processor, when in operation, determines whether data becoming available for transmission is the second periodic data for which the radio resources are reserved, by determining that the data belongs to the same logical channel as the first periodic data.

3. The transmitting device according to claim 1 , wherein the processor, when in operation, determines whether data becoming available for transmission is the first periodic data based on whether the data belongs to a specific logical channel, and in the affirmative case, the processor, when in operation, determines to reserve the radio resources for the later point in time.

4. The transmitting device according to claim 2 , wherein in case the data belongs to the same logical channel as the first periodic data, the processor, when in operation, further determines whether radio resources have been reserved, and in the affirmative case, determines to delay the second periodic data until the later point in time for which the radio resources are reserved, and wherein in case the data does not belong to the same logical channel as the first periodic data, the processor, when in operation, determines to transmit said data at an earliest point in time, including autonomously selecting other radio resources to be used for the transmission of the data.

5. The transmitting device according to claim 3 , wherein the specific logical channel is configured based on a priority indication and/or a periodicity indication for the first periodic data provided by an upper layer in the transmitting device, and wherein the periodicity of the periodic data is indicated by the upper layer in the transmitting device together or separately from the priority indication.

6. The transmitting device according to claim 1 , wherein a maximum delay time is configured, wherein the processor is configured to determine a number of times the first periodic data is delayed more than the maximum delay time, and in response to the determined number of times being greater than a predetermined number, further periodic data, becoming available for transmission after the determination, is transmitted at an earliest point in time upon becoming available for transmission.

7. The transmitting device according to claim 6 , wherein the transmission of the second periodic data at the earliest possible point in time includes the processor, in operation, autonomously selecting other radio resources to be used for the transmission of the second periodic data, and wherein scheduling information transmitted together with the second periodic data indicates the selected radio resources used for transmitting the second periodic data and further indicates reserved radio resources usable at the later point in time by the transmitting device to transmit third periodic data, and wherein the maximum delay time is indicated from an upper layer together with or separately from a priority indication of periodic vehicular data.

8. The transmitting device according to claim 1 , wherein in case an indication is received for the second periodic data indicating that the periodicity for the second periodic data is changed, the second periodic data is transmitted at an earliest point in time.

9. The transmitting device according to claim 1 , wherein a maximum number of simultaneous radio resource reservations is configured for the transmitting device to limit a number of radio resource reservations the transmitting device makes simultaneously.

10. The transmitting device according to claim 1 , wherein the reserved radio resources are the same or are different from the radio resources used for transmitting the first periodic data, and wherein in case that the reserved radio resources are the same as the radio resources used for transmitting the first periodic data, one field of the first scheduling information indicates both the reserved radio resources and the radio resources used for transmitting the first periodic data, and wherein the reserved radio resources are defined by at least frequency-time resources and a modulation and coding scheme to be used for the transmission.

11. The transmitting device according to claim 1 , wherein the reserved radio resources are reserved for the second periodic data, such that the reserved radio resources are to be used exclusively for transmitting the second periodic data.

12. The transmitting device according to claim 1 , wherein the other data is aperiodic data or other periodic data and is transmitted by the transmitting device by the processor autonomously selecting other radio resources and the transmitter transmitting the other data using the selected other radio resources.

13. The transmitting device according to claim 1 , wherein the periodic data comprises Cooperative Awareness Messages, CAM, triggered periodically to provide updated vehicular status information, and the aperiodic data comprises Decentralized Environmental Notification Messages, DENM, triggered by vehicle-related safety events.

14. The transmitting device according to claim 1 , wherein the transmitter, when in operation, transmits second scheduling information together with the second periodic data indicating the reserved radio resources used for transmitting the second periodic data.

15. The transmitting device according to claim 1 , wherein radio resources are scheduled semi-persistently by a base station to transmit fourth periodic data, wherein in case the periodic data becomes available for transmission before the semi-persistently scheduled radio resources, the transmitting device does not trigger and does not transmit a scheduling request for requesting further radio resources from the base station to transmit the periodic data.

16. The transmitting device according to claim 15 , wherein the periodic data is delayed until the semi-persistently scheduled radio resources such that the transmitter transmits the periodic data using the semi-persistently scheduled radio resources.

17. The transmitting device according to claim 1 , wherein the transmitting device is a vehicular mobile terminal, a road side unit, or a mobile terminal, and the periodic data is periodic vehicular data or periodic non-vehicular data.

18. The transmitting device according to claim 1 , wherein the transmitting device, when in operation, performs sensing of the reserved radio resources by: monitoring for scheduling information transmitted by another device indicating radio resources reserved by the another device for another later point in time, and excluding the radio resources reserved by the another device from a plurality of radio resources when reserving the radio resources from the plurality of radio resources at the later point in time.

19. The transmitting device according to claim 1 , wherein a maximum delay time is configured, and the processor, when in operation: determines whether the second periodic data is to be delayed by more than the maximum delay time, and in response to determining that the second periodic data is to delayed by more than the maximum delay time, transmits the second periodic data at an earlier time than the maximum delay time.

20. A method for transmitting periodic data via a sidelink interface from a transmitting device to one or more receiving devices, wherein the transmitting device autonomously selects radio resources for transmitting periodic and aperiodic data via the sidelink interface, the method comprising the following steps performed by the transmitting device: transmitting first periodic data together with first scheduling information to the one or more receiving devices, the first scheduling information indicating radio resources used for transmitting the first periodic data and further indicating reserved radio resources usable at a later point in time by the transmitting device to transmit second periodic data, wherein the first scheduling information includes a field indicating the later point in time for which the radio resources are reserved; determining the later point in time for the reserved radio resources based on a periodicity of the first and second periodic data; delaying the second periodic data until the later point in time and transmitting the second periodic data at the later point in time using the reserved radio resources indicated by the first scheduling information; and transmitting other data than the first and second periodic data in response to the other data becoming available for transmission.